The present invention is concerned generally with driving rotary members in rotation, for carrying out various operations thereon such as testing or measurement or machining operations.
For the purposes of driving rotary members of any kind in rotation, it is appropriate to use belt drives in which the drive belt is passed around the rotary member to be driven thereby, or the drive belt bears against the rotary member in substantially tangential relationship therewith. A belt drive is generally preferred whenever the situation involves driving in rotation rotary members which may be of different diameters. To provide for such a drive to a rotary member, it is only necessary for the rotary member to have a surface portion of circular cross-section, against which the drive belt can therefore bear for the purposes of driving the rotary member. The drive belt can be used not only for transmitting drive moments from a drive motor to the rotary member, but also for transmitting a braking moment to the rotary member in order to bring it to a halt. Particularly when dealing with rotary members which do not include any drive members or portions of their own, for example rotary members in the form of tubes or cylindrical rotary members, a belt drive is frequently used instead of a universally jointed shaft drive.
Particularly when the belt drive involves the transmission of high levels of torque, and particularly when the belt drive is in use over a prolonged period of time, the drive belt may suffer from a considerable amount of wear and may also be subject to fatigue of the material forming the drive belt. Those considerations not only result in impaired transmission of the torque, but they can also give rise to a major risk factor in terms of safety, in particular in the event of the drive belt suffering from a breakage as a result of wear and/or fatigue thereof.